There exists a variety of different stacked assemblies and structures in the context of electronics and electronic products. The motivation behind the integration of electronics and related products may be as diverse as the related use contexts. Relatively often size savings, weight savings, cost savings, or just efficient integration of components is sought for when the resulting solution ultimately exhibits a multilayer nature. In turn, the associated use scenarios may relate to product packages or food casings, visual design of device housings, wearable electronics, personal electronic devices, displays, detectors or sensors, vehicle interiors, antennae, labels, vehicle electronics, etc.
Electronics such as electronic components, ICs (integrated circuit), and conductors, may be generally provided onto a substrate element by a plurality of different techniques. For example, ready-made electronics such as various surface mount devices (SMD) may be mounted on a substrate surface that ultimately forms an inner or outer interface layer of a multilayer structure. Additionally, technologies falling under the term “printed electronics” may be applied to actually produce electronics directly and additively to the associated substrate. The term “printed” refers in this context to various printing techniques capable of producing electronics/electrical elements from the printed matter, including but not limited to screen printing, flexography, and inkjet printing, through a substantially additive printing process. The used substrates may be flexible and printed materials organic, which is however, not always the case.
Furthermore, the concept of injection molded structural electronics (IMSE) actually involves building functional devices and parts therefor in the form of a multilayer structure, which encapsulates electronic functionality as seamlessly as possible. Characteristic to IMSE is also that the electronics is commonly manufactured into a true 3D (non-planar) form in accordance with the 3D models of the overall target product, part or generally design. To achieve desired 3D layout of electronics on a 3D substrate and in the associated end product, the electronics may be still provided on an initially planar substrate, such as a film, using two dimensional (2D) methods of electronics assembly, whereupon the substrate, already accommodating the electronics, may be formed into a desired three-dimensional, i.e. 3D, shape and subjected to overmolding, for example, by suitable plastic material that covers and embeds the underlying elements such as electronics, thus protecting and potentially hiding the elements from the environment.
It is common to have buttons or other control means in the electronic devices. These may be, for example, push buttons based on application of mechanical force, or reactance sensing devices, such as based on capacitive sensing. In some known solutions relatively large electrodes are being arranged on the surface or close to the surface of the device, such as on a printed circuit board (PCB). There may then be an additional layer arranged to cover the electrodes and the PCB. In order to operate the sensing device, an electric field may be produced at the sensing element, such as an electrode, and controlled such as to obtain sufficiently good signal to noise ratio in order to detect the presence of a finger or an object utilized to control the operation of the device, for instance.
The known solutions have disadvantages, such as with large electrodes it's challenging to design solutions with close by adjacent sensors. It also takes room from other electronics. Sensing sensitivity and interferences may cause various issues. Known solutions are constructed with separate components, thus increasing costs and assembly time. These components may further become loose when they are subject to pressures present in injection molding process. The resulting structures become more complicated affecting manufacturability.